Die-casting apparatus



Aug. 22, 1933. 'r. c. KORSMO DIE CASTING APPARATUS Original Filed June29, 1951 5 Sheets-Sheet 1 Zhwentor: Ci ars/r10,

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DIE CASTING APPARATUS Original Filed June 29, 1931 5 Sheets-Sheet 4Junentor:

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DIE CASTING APPARATUS Original Filed June 29, 1931 S'Sheets-Sheet 5 j Li Snncntor:

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Patented Aug. 22, 1933 UNITED STATES PATENT OFFICE Madison-KippCorporation, Madison, Wis., a

Corporation of Wisconsin Original application June 29,

1931, Serial No.

Divided and this application April 16,

1932. Serial No. 605,756

9 Claims.

Thisinvention pertains to die casting apparatus and more particularly toapparatus for the manufacture of die castings from magnesium and similarmetals.

This application is a division of my copend ing'application Serial No.547,737, filed June 29, 1931, relating to an improved method of diecasting for the practice of which the apparatus of the presentapplication was particularly designed. No claim, therefore, is madeherein to the method, the same being fully covered by said priorapplication.

In die casting with certain metals, such "as magnesium, for example, ithas been found that exposure of the molten metal to the atmosphere or toany other combustion-supporting medium,

causes the metal to burn. This results in the production of defectivecastings, and also occasions numerous time-consuming and annoying delaysin the operation of the casting apparatus.

It is the primary purpose of the present invention to devise a diecasting apparatus, wherein such undesirable burning of the molten metal'is prevented and production of high class die cast ings at a rapid rateis accomplished. In general, this is effected by excluding thesurrounding atmosphere, and any other combustion-supporting medium, fromcontact with the metal while it is in a molten state. At the same time,direct application of fluid pressure to the molten metal for the purposeof forcing it into the die cavity is permitted.

In one of the more common types of die casting machines, a pressurechamber or goose neck receives molten metal from a melting pot, and thena pressure fluid, such as compressed air, is released into directcontact with the metal to force it from the goose neck into the die. Itis one of the particular objects of the present invention to devise aconstruction whereby the die casting of magnesium and similar metals maybe accomplished in this type of machine.

A practical embodiment of my specially designed machine for carrying outthe method is illustrated in the accompanying drawings, wherein:-

Fig, 1 is a fragmentary side elevation of the machine with the combinedmelting pot and goose neck unit in die-charging position ready for thepressure fluid to be released to the goose neck to force molten metaltherefrom into the closed die:

Fig. 2, a plan view with the parts in the positions of Fig. 1;

Fig. 3, a fragmentary side elevation, similar in part to Fig. 1, thecombined melting pot and goose neck being shown in section in thecharge-receiving position of the goose neck, the die-charging positionthereof being indicated in dotted lines;

Fig. 4, an elevational view of the nozzle end of the combined goose neckand melting pot unit and its actuating means, the unit being in itsraised position:

Fig. 5, a composite, perspective view of the combined melting pot andgoose neck with the two parts disconnected and separated to show thedetails thereof;

Fig. 6, a fragmentary longitudinal section of the drain spout and valvefor the melting pot;

Fig. 7, an end elevation of the valve for controlling communicationbetween the melting pot and the interior of the goose neck;

Fig. 8, a fragmentary, vertical section showing the relation of themetal control valve of Fig. 7 and the melting pot cover both in theraised and lowered positions of the melting pot;

Fig. 9, a side elevation of a distributor unit for feeding predeterminedquantities of powdered material to the pressure fluid line leading tothe goose neck;

Fig. 10 an elevation of ,the distributor unit and its' actuatingmechanism looking 'from the left end of the machine as shown in Fig. 1,the powder-receiving hopper being shown in section; and

Fig. 11, a plan of the distributor with the pawl-and-ratchet operatingmechanism removed and the hopper shown in section.

In order to disclose the invention fully, it is not necessary toillustrate thecomplete die casting machine by which my improved methodof casting is practiced; nor to describe in detail the construction andoperation of the means for opening and closing the die. However, suchreference will be made to all parts and their mode of operation as isessential to a complete understanding of the present invention. Detailsof construction and operation of the devices referred to are fully setforth in my earlier Patents Nos. 1,607,677, November 23, 1926, and1,631,686, June 7, 1927, to which reference is made for this purpose.

The machine comprises a bed 1 supporting a gear housing. 2.- The ends ofa series of guide rods 3, 3, 3', 3' are secured in the left hand wall 2'of housing 2 and their opposite ends find support in hot plate 4. Thishot plate, to which is attached the stationary die part 5, is mounted inthe upper part of a frame member 6, the latter being supported above thebed of the machine by rods 7, 7' and their bearing blocks 8, 8' (theright hand set of blocks not being shown) 2 Attached to die carriage 9,which is slidably mounted on guide rods 3, 3, 3', 3', is the movable diepart 10.

An open top furnace 11, provided with gas burners or other suitableheating means 12, is

secured to the bed of the machine beneath frame member 6. Pivotallysupported at its left end for movement in the upper part of furnace 11is a combined melting pot and goose neck unit for supplying molten metalto the die. Melting pot 13, which comprises the lower part of the unit,is formed about its upper edge with a flange 14 having threaded openings14' and side extensions 15, 15', with which latter certain operatingmeans coact, as hereinafter described, to raise and lower the free endof the unit. Secured by screws 16 to the top of melting pot 13 is a;casting which serves to cover tightly the otherwise open top of themelting pot and protect the molten metal therein from the surroundingatmosphere. This casting comprises a'goose neck or pressure chamberportion 17 and a cover portion 18, the edges of the latter beingperforated, as indicated at 18', to receive screws 16, which extendtherethrough into openings 14'. Cover portion 18 is also provided withside extensions 19, 19, corresponding to extensions 15, 15' on meltingpot 13. A removable discharge nozzle 17 fitted to the outer end of gooseneck 17, is adapted to communicate with the die cavity through aperforated nipple plate 16 pivoted on hot plate 4, when the parts are inthe die-charging position of Fig. 1.

A standard 20 on the bed of the machine provides pivotal support for theleft end of the goose neck and melting pot unit, whereby the .free ornozzle end thereof may swing towards and from the die. Standard 20 andmelting pot cover 18 are provided for this purpose with pairs ofperforated lugs 21, 21' and 22, -22', re-

spectively, while a pivot pin 23 extends through the lugs to support theunit in place.

Cover 18 is formed centrally with a domeshaped metal-receiving portion24 surrounding the upright leg of goose neck 17 (see Fig. 3). An opening25 is provided in this portion of the cover through which metal ingotsare fed to the melting pot. This opening is closed by a plug-type cover26 having a supporting flange 27 about its edges and'a handle 28. Askirt or shaft 29, the

purpose of which will appear later, is formed on the underside of cover18 about opening 25. Trunnions 30, 30, formed on the outer corners ofmelting pct 13, are to assist in removal of the melting pot unit, whenthisis desired. Molten metal is supplied to goose neck 17 from themelting pot through a port 31 in the inclined arm of the goose neck.Port 31 is controlled by a stationary, plug-type valve 32 mounted on abracket 33 attached to hot plate 4 and extending through an opening 34in the melting pot cover 18. With this arrangement, port 31 is openedwhen the goose neck is lowered and automatically closed as the nozzle17' moves towards the closed die.

A'bushing 35 is secured in opening 34, the passage 36 through thebushing being of sufficient size to fit snugly about valve 32 at itsupper end, while the passage flares downwardly to allow for the swingingmovements of the melting pot and goose neck unit toward and from thedie. This is clearly shown in Fig. 8, where the melting pot coverappears in full lines in its lowered position and in dotted lines in thedie-charging position.

. swinging of. melting This arrangement completely prevents entrance ofair to the molten metal at this point.

' It will be noted from Fig. 3 that furnace 11 is formed with a rabbet37 in its upper edge 38 to receive the flanged edge of melting pot 13.Rabbet 37 is inclined at 39 and 39' to permit pot 13 about pivot pin 23.Slots 40, 40' in the upper edge of the furnace freely receive trunnions30,30, while similar slots 41, 41' normally accommodate liftingextensions 15, 15' at the swinging end of the melting pot.

As hereinafter described, compressed air is admitted to goose neck 17through nipple 42 and perforated pipe 43 (Fig. 3), striking against cap44 and acting downwardly to force the molten metal from the goose neckinto the die.

. Melting pct 13 is provided with a drain spout 45 having a passage 46therethrough, the spout projecting freely through opening 47 providedfor this purpose in the end wall of furnace 11. Mounted on the outer endof spout 45 is a plate 48 having a cylindrical extension 49formedthereon and projecting into the outer end of passage 46, wherebythe'escape of metal is normally prevented. Plate 48 is supported by apair of 1 stud bolts 50, 50 fixed in the end of spout 45' and extendingfreely through openings in the plate. Nuts 51, 51' serve to secure theplate 48 in closed position, as shown in Fig. 6.

Extension 49 of plate 48 is chamfered at 52,

into communication with groove 53. Since the outer end of groove 53 isnow open, free passage for draining of the metal is provided. The flowmay be stopped immediately by simply pushing the plate 48 back intoposition, after which nuts 51, 51' are screwed up.

The mechanism for opening and closing the die and for raising themelting pot and goose neck unit into die-charging position will now bedescribed.- A drive shaft 54 is journaled at its ends in the sides ofhousing 2. A cover 55 is provided for the housing and conceals thegearing for drive shaft 54. The die operating parts. and the goose neckand melting pot unit oper-- ating parts about to be described beingduplicated on either side of the machine, only the forward set will bereferred to in detail. The corresponding parts at the rear are indicatedby primed numbers. A crank 56 fixed to the front end of shaft 54 has acam 57 secured fast there-' to. This cam carries a roller 58 engaging aslot 59 in the end of connecting rod 60. A roller 61 mounted forrotation on the inner face of connecting rod engages at all times withthe edge of cam 57.

At their opposite ends, the two connecting rods 60, 60' are joinedtogether by a cross member 62. This cross member is fixedly secured ondie carriage pusher rods 63, 63 intermediate their ends, the rods beingextended on either side of the cross member and at the right sidethereof passing through suitable guideways 64, 64 provided for thispurpose on the inner wall 2 of housing 2 (see Figs. 1 and 2). Splitbearings 65, 65' on die carriage 9 slidably connect the carriage topusher rods 63, 63' for a purpose explained later.

molds, or for other purposes, 11

as shown in the same figure. goose neck nozzle 1'7 is raised by theconnections On each side of die carriage 9, pusher rod 63 is threaded toreceive a pair of nuts 66 to the right and a pair of nuts 6'1 to theleft of the die carriage. A spring 68 located between nuts 66 and thedie carriage serves to urge the carriage towards the left and againstnuts 6'7.

Also pivotally connected at one end tocross member 62 is an elevatorpusher rod 69. The left hand end of this rod has a 'pin-and-slotconnection at '70. with the upper end of a lever '71 pivotally supportedat its lower end by a pin 72 carried by frame member 6. A link '73 ispivotally connected to lever '71 at '74, while the opposite end of thelink is bifurcated to receive a pivot pin 75. Pin '75 pivotally connectslink '73 with the upper end of a crank '76, which is fixed to the Outerend of a short shaft '77 mounted for oscillation in a bracket '78securedto frame member 6. An eccentric is provided on the inner end ofshaft '77 which is adapted to coact with the side extensions 15, 15 onthe melting pot and goose neck unit to effect raising and permitlowering of the unit in the operation of the machine. As shown, thiscomprises a disc '79 formed integrally with shaft 7'7 and an integraleccentrically arranged stud 80, which latter engages directly withmelting pot extensions 15, 15', as appears most clearly in Fig. 4.

Such of the mechanism so far described as is not claimed hereinafter iscovered by my prior Patents Nos. 1,607,677 and 1,631,686, supra, and1,590,246, June 29, 1926. Referencemay be had to these for furtherdetails.

In operation, when power is applied to drive shaft 54 to rotateitclockwise, as shown in Fig. 1, connecting rods 60; 60' move to theleft and impart a corresponding movement to cross member 62, diecarriage pusher rods 63, 63, and elevator pusher rods 69, 69, untilthese parts reach the die-charging position of Fig. 1. As a result ofthis movement of the parts mentioned, die carriage 9 is moved to theleft orr'guide rods 3, 3, 3, 3, until movable die part 10 engages fixeddie part 5, Simultaneously,

described into contact with nipple plate 16. Following this, the gooseneck and melting pot unit,

as will appear shortly, has a final upward movement which carries itinto registry with the closed die through the opening in the nippleplate, the position shown in Figs. 1 and 2.

Die carriage 9 is preliminarily adjusted on the guide rods and securedby nuts 66, 66', 6'7, 67', so that the die partsand are brought togethershortly before cross member 62 completes its movement to the left.Hence, when the die parts are brought together, cross member 62continues its movement to the left and causes springs 68, 68' to becompressed against die carriage 9, pusher rods 63, 63 sliding freelythrough the die carriage to permit this action. During this shortrelative movement between cross member 62 and die carriage 9, the gooseneck and melting pot unit is elevated to the die-charging positionindicated in dotted lines in Fig. 3. Simultaneously, the flow of moltenmetal from melting pot 13 into the goose neck is cut off by valve a Inorder to insure accurate seating of valve 32 and provide proper tensionbetween the parts, the valve is suspended from bracket 33 by a resilientmounting. This is shown in detail in Fig.-

'7. wherein the stem 81 of the valve is threaded into the lower side ofa spring metal connecting member 82. A screw 83 extends through anopening in bracket 33 and has threaded connection with the upper part ofspring member 82. This spring member is formed with enlarged curvedportions 84, 84' at its ends, while centrally there are provided opposedflat surfaces 85, 85. The latter provide a ready means for insertion ofa gage to determine the tension between the valve 32 and goose neck 17,when the latter is in-diecharging position. The resilient mounting ofvalve 32 also permits any necessary lateral movement of the valve whichmay be caused by the swinging movements of the melting pot and gooseneck unit.

After the parts have arrived at the die-charging position of Fig. 1,compressed air, or other suitable pressure fluid, is admitted to therear end of the goose neck to force the molten' metal into the die. Themeans for accomplishing this will be described shortly. After the chargeof metal from goose neck 1'7 has been forced into the closed die andpermitted to freeze, the die and goose neck unit actuating mechanismoperates in the opposite direction, i. e., to the right, carryingconnecting rods 60, to the right, together with cross member 62. As aresult, the goose neck and melting pot unit starts to descend towardsthe full line, or charge-receiving position of Fig. 3. During thismovement, it

will be noted that valve 32 is unseated, so that molten metal may flowagain into goose'neck 17 through port 31.

As cross member 62 and pusher rods 63, 63 continue their movement to theright, nuts 6'7, 6'7 engage die carriage 9 and move it to the right, soas to separate'the die parts 5 and 10. The parts continue their movementto the right, until the full open position is reached, when the machineis ready for the next casting operation.

The means for supplying the pressure fluid to goose neck 1'7 will bedescribed now. As indicated in dotted lines in Figs. 1 and'3, nozzle 42serves to-connect goose neck '17 to a pressure fluid connection 86, whenthe goose neck is in die-charging position. Connection 86 is mounted onstandard 20 and has a passage 8'7 therethrough. Suitable counterweightedmeans serve to urge fluid connection 86 to the right'into sealingengagement with nozzle 42. This mechanism forms no part of the presentinvention, but is fully disclosed and claimed in my copendingapplication, Serial No. 476,909, filed August 21, 1930 (Patent No.1,877,896, dated September 20, 1932).

A pipe 88 leads from the outer end of passage 87 in connection 86 to asuitable source of pressure fluid supply. Certain valve mechanisminterposed in,pipe line 88, as described below, is adapted to beactuated automatically when the die is closed to supply pressure fluidto the goose neck through connection 86, and thereby force the moltenmetal from the goose neck into the die. The supply of pressure fluid isthen automatically cut off and the pressure fluid vented from the gooseneck and connected parts before the die opens.

Inlet valv'e casing 89 is located in pipe line 88, while the stem of anormally closed inlet valve 90 projects therefrom for actuation, ashereinafter described, to permit passage of pressure fluid to the gooseneck. As shown in Fig. 2, a pipe 91 connects with inlet valve casing 89between the goose neck and inlet valve 90, the outer end of pipe 91being connected to an exhaust valve casing 92.

connections through exhaust port 94 in casing 92, after a die-chargingoperation has taken place. 1

With the described arrangement of the parts, it is clear that, wheninlet valve is actuated, compressed air will flow through pipe 88 togoose neck 17. At the same time, compressed air will fill pipe 91 andexhaust valve casing 92. -However, since exhaust valve 93 is closed, thecompressed air cannot escape at this point and opertrolled by the maindrive shaft 54. As shown in Figs. 1 and '2, a cam 95 is provided on thefront end of shaft 54, the periphery thereof being provided with a mainsurface 96 and a raised operating surface 97. Pivotally mounted at 98 onhousing 2 is a bell crank 99 having a roller 100 at the end of one armthereof engaging the periphery of cam 95. The other arm of bell crank 99is engaged by the right hand end of thrust rod 101 which extends throughthe hollow guide rod 3. The opposite end of thrust rod 101 projectsbeyond hot plate 4 for engagement with-the stem of inlet valve 90 toopen the valve at the proper time. Coil spring 102, interposed between afixed collar 103 on thrust rod 101 and wall 2' of the gearhousing,serves to urge the thrust rod to the right and thus force roller 100against cam 95.

When roller 100 is in engagement with cam surface 96, the left end ofthrust rod 101 is spaced from the stem of inlet valve 90, so that thelatter remains closed. As shaft 54 revolves, roller'100 is engaged bycam projection 9'7, thereby forcing thrust rod 101 to the left by meansof the described connections and operating the inlet valve so thatcompressed air passes to the goose neck. As soon as cam surface 97 haspassed under roller 100, spring 102 serves to move pusher rod 101 backto its original position, permitting inlet valve 90 to close.

The mechanism for operating exhaust valve 93 is identical with that forthe inlet valve, except for the form of the operating surface of the cammember. This cam member 104 is secured to the rear end of shaft'54. Thecam has a main peripheral surface 105 and a depressed surface 106. Aslong as roller 100 is in engagement with cam surface 105, whichcomprises the greater part of the periphery of the cam, thrust rod 101is held to the left to maintain exhaust valve 93 in open position tovent the parts. As shaft 54 revolves, roller 100' engages the depressedcam surface 106, thereby permitting spring 102' to force thrust rod 101'to the right to enable exhaust valve 93 to close.

With the arrangement of parts and the formation of cams 95 and 104 asthey appear in Figs.

1 and 2, the sequence of operations is as follows: Starting with thecharge-receiving position of goose neck 17, shown in solid lines in Fig.3, it will be seen that at this time the die is. open and the sealbetween air nozzle 42' and air connection 86 is broken to permit ventingof the 75- parts at this point. At this time the position of cam 104 issuch that'exhaust valve 93 is held open to vent the remaining parts ofthe pressure fluid system to the atmosphere.

As drive shaft 54 continues to revolve,.nozzle 42 seats againstconnection 86, the die is closed, and metal discharge nozzle 17 .of thegoose neck forces nipple plate 16 against the die. By this time, cam 104has revolved to permit closing of exhaust valve 93. Shortly after this,raised portion 97 of cam 95 acts to open inlet valve 90 for a briefinterval. During the entry of compressed air as described, exhaust valve93 remains closed, but shortly after the inlet valve has closed, cam 104operates to again open the exhaust valve to vent the parts. The exhaustvalve remains open until the die closes the next time. 1

Shortly after exhaust valve 93 opens, pusher rods 69, 69' operate, ashereinbefore described, to permit goose neck nozzle 17 and nipple plate16' to drop away from the under side of the die and resume theiroriginal positions. The'die then opens andconnection at the rear of thegoose neck with the compressed air system is broken. Continued movementof the parts brings them back to the original charge-receiving positionof Fig. 3.

It is clear that with the specially designed construction of the meltingpot and goose neck unit described, molten magnesium or similar metalsmay be used readily for the manufacture of die castings, without dangerof the surrounding atmosphere coming in contact with the metal andcausing burning thereof. In practice, metal ingots are fed to meltingpot 13 through opening 25 and metal-charging shaft 29, so as to keep themetal level as high as possible. Generally this is well up in themetal-receiving dome 24, but just below the bottom of cover 26, asindicated by the dot and dash line in Fig. 3. In this manner, part ofthe upper surface of the metal is maintained in contact with theunderside of cover 18. Skirt or metal-charging shaft 29 serves to sealoff nearly all of the remaining molten metal surface from opening 25 andthereby reduce Location of the molten metal in dome 24 surrounding theupper portion of the inner leg of pressure chamber 17 also assistsmaterially in keeping the metal in the pressure chamber in a completelymolten state. The additional molten metal in dome 24 also increases thehydrostatic pressure of the body of metal at inlet 31 leading topressure chamber 17 and accelerates passage of metal therethrough whenthe port is opened. Ingot feeding shaft 29, being within cover 18 and incontact with the molten metal, is maintained at a high temperature,thereby facilitating melting of the ingots placed therein.

Special provision is made to permit direct application of fluid pressureto molten magnesium, or similar metals, to force the metal from thegoose neck 17 into the die. and at the same time,

preclude possible burning of the metal'at this point. It has been foundthat the introduction of a quantity of suitable reagent, such aspowderedsulphur, into the pressure fluid acting against the molten metal ingoose neck 1'? entirely prevents burning of the magnesium metal. This isaccomplished automatically by the distributor unit shown in detail inFigs. 9, and 11.

The distributor unit comprises a hopper 107 having a pivoted cover 108provided with a swinging fastener 108'. The lower part of the hopper isformed to provide a passage 109 the ends of which are threaded, wherebythe unit is interposed in the compressed air pipe line 88. transverselyarranged cylindrical enlargement 110 formed on the bottom of hopper 107is provided with a cylindrical chamber 111 which is open at one end.Chamber 111, as shown in Fig. 10, intersects the upper part of passage109 so as to provide an opening 112 through which a predeterminedquantity of powdered sulphur is fed to passage 109 during each cycle ofoperation of the machine. An elongated opening 111 connects hopper 107with chamber 111, while the feeding of powdered surphur from the hopperto passage 109 is controlled by a distributor shaft 113 arranged forstep-by-step rotation in chamber 111. The surface of shaft 113 isprovided with a series of longitudinally disposed, parallel pockets 114into which the powdered sulphur. settles and by means of which it ismeasured and emptied into passage 109.

Endwise movement of shaft 113 is prevented by a pin 110' mounted in thebase of the hopper and projecting into an annular groove 113' in theshaft (Fig. 11). A spring-pressed ball 109' engages successivelydepressions 112' provided on flange 114' of shaft 113 to insureregistration of opening 111' in the bottom of the hopper with eachsucceeding pocket 114.

The desired step-by-step rotation of distributor shaft 113 isaccomplished by arranging for its actuation by lever 71, during theperiodic movements of the latter as it raises the goose neck and meltingpot unit from charge-receiving to diecharging position in the successivecycles of operation of the machine. The outer end of distributor shaft113 is reduced at 115 to receive a ratchet wheel 116 which is fixedthereto. Mounted intermediate its ends for oscillatory movement on thereduced outer end 117 of shaft 113 is a lever I i 118. A nut 119threaded on the end of shaft 113 serves to hold lever 118 in place. Thelower end of lever 118 is pivotally connected by a link 120 to" lever'71 near its upper end. as shown in Fig. 1.

Pivoted on the upper end of lever 118 is a pawl 121 the lower end ofwhich engages the teeth of ratchet wheel 116. As shown in Fig. 10, theupper end of pawl 121 is provided with a laterally projecting pin 122extending over the upper end of lever 118. Mounted in a recess 123 inthe upper end of lever 118 is a plunger 124. A coil spring 125 in thelower end of recess 123 urges plunger 124 outwardly into engagement withpin 122, thereby retaining the pawl in engagement with ratchet wheel116.

5 Thus, as the goose neck and melting pot unit swings up intodie-charging position, as hereinbefore described, the quantity ofpowdered sulphur deposited by distributor shaft 113 in passage 109 iscarried by the compressed air, which 'is released by inlet valve at thistime, into the rear end of goose neck 17. In this manner, the powderedsulphur is intimately mixed and reacts with the compressed air at therear of the molten magnesium metal in the goose neck and destroys- 5{the combustion-supporting properties thereof, so 1 that the moltenmetal cannot burn. A sufficient amount of sulphur should be injectedinto the air In other words, the oxygen of the air combines with thesulphur to form sulphur dioxide, while the nitrogen of the air combineswith a portion of the magnesium to form magnesium nitride. Thus, thereis a complete absence of any medium in the vicinity of the molten metalwhich will support combustion and thereby permit the metal to burn.

In carrying out the improved method with the apparatus described,contact of the surrounding atmosphere and the pressure fluid with themolten magnesium metal is prevented, thereby precluding possible burningof the metal and permitting the rapid'production of high classdie-castings.

The terms and expressions employed herein are used as terms ofdescription and not of limitation, and there is no intention, in. theuse of these terms and expressions, of excluding any equivalents of thefeatures shown and described or' portions thereof, but it is recognizedthat variousv modifications are possible within the scope of theinvention claimed.

What is claimed is:

1. The combination in a die-casting machine 'of a container for moltenmetal; a pressure chamber mounted in the container and adapted toreceive molten metal therefrom; means for effecting such transference ofmetal, the construction and arrangement of the parts being such thatcombustion-supporting media are excluded from the molten metal so as toprevent burning thereof; means for supplying pressure fluid to thepressure chamber to force the molten metal therefrom into a die; andmeans for measuring and supplying to the pressure fluid a measuredquantity of a substance adapted to react with the pressure fluid in thepresence of heat to form a gas inert toward the metal being cast.

2. The combination in a die-casting machine of a melting pot having acover; a goose neck supported in the melting pot by said cover, thecover being formed with a dome shaped metalreceiving portion surroundingone of the legs of the goose neck; and a depending metalcharging shaftfor the pot located in said domeshaped portion.

3. The combination in a die-casting machine of a, melting pot having acover; a goose neck supported in the melting pot by said cover andhaving a metal discharge nozzle projecting therefrom, the other leg ofthe goose neck extending through the cover and being surrounded by adome-shaped metal-receiving portion thereof;

and a removable lid closing an opening in said dome-shaped portion, saidportion being formed with a continuous skirt about said opening adaptedto project into the molten metal.

' 4. In a die-casting machine, the combination of a container for moltenmetal; means for supplying pressure fiuid to said container to forcemolten metal therefrom into a die connected to the container; and meansconnected to the pressure "fluid supply means for measuring andsupplying to the pressure fluid a measured quantity of a. substanceadapted to react with the pressure fluid in.the presence of heat to forma gas inert 7 toward the metal being cast.

5. In a die-casting machine, the combination of a container for moltenmetal; means for Supplying compressed air to said container to forcemolten metal therefrom into a die con nected to the container; and meansconnected to the compressed air supplying means for measuring andsupplying a measured quantity of powdered sulphur to the compressed airto prevent burning of the molten metal.

6. In a die-casting machine, the combination of a melting pot; a gooseneck mounted therein and provided with an integral portion detachablyconnected to and forming a cover for the melting pot, said melting potand said goose neck being movable as a unit to connect the goose neck toand disconnect it from a die; actuating means for the melting pot andthe goose neck; and a valve mounted on a stationary part of the machinefor controlling a port in the goose neck adapted to connect theinterior-of the goose neck with the melting pot.

7. In a die casting machine having a frame, and a goose neck and meltingpot pivoted thereon to swing as a unit to and from a die mounted on theframe, said goose neck having a port for the passage of molten metalfrom the melting pot into the goose neck, the combination of a valveadapted to close said port when the goose neck is in die chargingposition; and a spring member attached to the frame and supporting thevalve, said spring member being formed with spaced, parallel portionsfor the insertion of a gauge.

8. The combination in a die-casting machine of a pressure chamberadapted for movement between an operative die-charging position and aninoperative position; actuating means for said pressure chamber; meansfor conducting pressure fluid to the-pressure chamber to force molten-metal therefrom into a die; a hopper, adapted to contain a powderedreducing agent, having an opening leading into the conducting means; amovable, charge-delivering member controlling said opening; andoperative connections, including a pawl and ratchet device, between saidmember and said actuating. means for causing a charge of the reducingagent to be delivered to the conducting means upon each movement of thepressure chamber towards die-charging position.

9. In a die-casting machine, the combination of a frame; a pivotedpressure chamber adapted for movement between die-charging andchargereceiving positions; a melting pot for supplying molten metal tosaid pressure chamber; valvecontrolled means for supplying pressurefluid to the pressure chamber-when in die-charging posi-.- tion to forcemolten metal therefrom into a die; means connected to the pressure fluidsupply means for feeding a substance to the pressure fluid to preventburning of the molten metal in the pressure chamber; actuating means forthe pressure chamber; and common driving means for operating the partsinorder, so that said substance is delivered to the pressure fluid meansand then the pressure fluid means are operated after the pressurechamber has reached die-charging position. v v TORBJORN C. KORSMO.

